You seem to be upset and disappointed at your opponent's decision to claim the win on time rather than allowing the game to continue. It suggests that you value the experience of playing the game itself and the exploration of difficult positions, rather than solely focusing on the outcome. While your sentiment is valid, it's important to recognize that different players have different approaches to the game.
To be honest, I would have done the same to you because I could care less about your feelings or what I would have potentially learned about "how a very difficult chess position might have resolved had we played it out". Just give me your rating points
I have a number of games on hold while -- instead of claiming a win on time -- I wait for my opponent to reappear. Today a missed a deadline by a few minutes, and -- in the midst of a very challenging and interesting game, my opponent had declared a win. I sent him the following message:
You actually pulled the plug in the middle of an interesting game, just minutes after my deadline expired? I would never have done that to you. It seems to me that you care only about winning or losing, but that you have no interest in the game itself. If the drama of a chess game mattered to you (not just who wins) why would you not have graciously allowed the game to continue? Now, neither of us will ever learn how a very difficult chess position might have resolved had we played it out.